How to create Rave/Strobe (Colour changing, flashing) lights in a Cycles animation
F-Curves modifier
Use nodes for your lights.
Add a HSV (far) Color ramp to feed the Emission shader color.
Now you just have to keframe the Factor of the color ramp and the Strenght of the emission node to a starting value.
Open the Graph editor and add a Noise modifier to each of the keframed channels and adjust the parameters to suit you needs. Factor should bounce between 0 and 1, while for the strenght you can go wild.

You can even use/combine others modifiers (sine, stepped interpolation....) to achieve other results.